두 종류의 부하곡선에 관한 공급지장시간기대치(LOLE)의 상호 변환관계성

이연찬(Yeonchan Lee),오웅진(Ungjin Oh),최재석(Jaeseok Choi),차준민(Junmin Cha),최홍석(Hongseok Choi),전동훈(Donghun Jeon) 대한전기학회 2017 전기학회논문지 Vol.66 No.3

This paper develops a conversion function and method transforming from daily peak load curve used LOLED [days/year] to hourly load curve used LOLEH[hours/year]and describes relationship between LOLED [days/year] and LOLEH [hours/year]. The indices can not only be transformed just arithmetically but also have different characteristics physically because of using their different load curves. The conversion function is formulated as variables of capacity and forced outage rate of generator, hourly load daily load factor and daily peak load yearly load factor, etc. Therefore, the conversion function (γ=φ(.)) cannot be simple. In this study, therefore, the function is formulated as linear times of separated two functions. One is an exponential formed conversion function of daily load factor. Another is formulated with an exponential typed conversion function of daily peak load yearly load factor. Futhermore, this paper presents algorithm and flow chart for transforming from LOLED[days/year] to LOLEH[hours/year]. The proposed conversion function is applied to sample system and actual KPS(Korea Power System) in 2015. The exponent coefficients of the conversion functions are assessed using proposed method. Finally, assessment errors using conversion function for case studies of sample system and actual system are evaluated to certify the firstly proposed method.

수질오염총량관리 단위유역 유량측정자료를 이용한 유황곡선 작성

박준대 ( Jun Dae Park ),오승영 ( Seung Young Oh ),최윤호 ( Yun Ho Choi ) 한국물환경학회 2012 한국물환경학회지 Vol.28 No.2

It is necessary to develop flow duration curve (FDC) on each unit watershed in order to analyze flow conditions in the stream for the management of Total Maximum Daily Loads (TMDLs). This study investigated a simple method to develop FDC for the general use of the curve. A simple equation for daily flow estimation was derived from the regression analysis between the 8-day interval flow data of a unit watershed and the daily flow monitoring data of an adjacent upstream region. FDC can be prepared with the calculation of daily flow by the equation for each unit watershed. An annual and a full-period FDC were drawn for each unit watershed in Guem river basin. Standard flow such as low and ordinary flow can be obtained from the annual FDC. Major percentile of flow such as 10, 25, 50, 75 or 90% can be obtained from the full-period FDC. It is considered that this simple method of developing FDC can be utilized more widely for the calculation of standard flow and the assessment of water quality in the process of TMDLs.

연구논문 : 부하지속곡선을 이용한 유량 조건별 수질특성 평가 -영본A 유역을 대상으로-

박진환 ( Jin Hwan Park ),김갑순 ( Kap Soon Kim ),정재운 ( Jae Woon Jung ),황경섭 ( Kyung Sup Hwang ),문명진 ( Myung Jin Moon ),함상인 ( Sang In Ham ),임병진 ( Byung Jin Lim ) 한국환경영향평가학회 2013 환경영향평가 Vol.22 No.4

본 연구에서는 영산강수계의 영본A 지점을 대상으로 평균 8일 간격의 실측된 수질과 유량자료를 이용 하여 유량 조건 별 수질특성을 평가함으로써 우리나라 오염총량관리 발전을 위한 기초 연구 자료를 제공하고자 하였다. 본 연구 결과를 요약하면 다음과 같다. This study was conducted to identify runoff characteristics of pollutants using flow duration curve(FDC) and load duration curve(LDC) in Youngbon A watershed during 2009~2011. A flow rate and pollutant load in the study watershed were estimated by equation of stage-discharge and discharge-loads rating curve. From these methods, BOD, T-N, and T-P have evaluated whether water quality standards would have attained. Results showed that BOD loads of about 50% plotted above the LDC, while T-N and T-P loads of about 50% plotted below the curve. It means that BOD of about 50% have exceeded the water quality criteria, while T-N and T-P of about 50% have complied with the water quality standards. Meanwhile, BOD, TN and T-P loads plotted above the LDC of low flows, implying that they were more affected by point pollution sources than nonpoint pollution sources in the study watershed.

유량-부하량관계식을 이용한 지석천 유역의 부하지속곡선 적용 및 유황별 유달율 산정

박진환 ( Jin Hwan Park ),김갑순 ( Kap Soon Kim ),황경섭 ( Kyung Sup Hwang ),이용운 ( Yong Woon Lee ),임병진 ( Byung Jin Lim ) 한국물환경학회 2013 한국물환경학회지 Vol.29 No.4

This study has been carried out to clarify the characteristics of discharge and pollutant loading according to flow conditions at jiseok stream watershed (JSW). A flow rate and pollutant load in the study watershed were estimated by equation of stage-discharge and discharge-loads rating curve. By using the methods above, I`ve evaluated the water quality (WQ) of the JSW if it is satisfied with the standard target. I`ve collected the data of BOD and T-P from the JSW every 8 days for the duration of 12 months. And then, I`ve schematized the data upon the load duration curve and the results showed me that the WQ of JSW was satisfied with the standard target. I`ve also collected the same data every each day for the duration of 12 months from JSW and have schematized the data again. And the results showed that it also was satisfied with the standard target. To be concluded, I`ve determined that point pollution sources of JSW gives more significant impacts to the WQ than non-point pollution sources of JSW and hence, as time goes, point pollution sources will keep depriciating the WQ of JSW. Therefore, further efforts will be required to JSW to maintain the WQ.

제한급전하는 오프그리드의 독립형 마이크로그리드 최적 설계 및 경제성 평가를 위한 일부하곡선 추정 방안에 관한 연구

남용현(Yong-Hyun Nam),윤석민(Seok-Min Youn),김정훈(Jung-Hoon Kim),황성욱(Sung-Wook Hwang) 대한전기학회 2019 전기학회논문지 Vol.68 No.1

There is a growing interest in various microgrid solutions that supply electricity 24 hours a day to off-grid areas where are not connected with the main grid, and Korea has many positive effects by constructing overseas microgrids as a country operating the emission trading scheme. Since it is not clear how to obtain load curves that is one of the inputs of the HOMER used to design a microgrid optimization plan, or it is necessary to examine whether electricity is supplied to the peak load level of the areas where have not received the electricity benefits from the viewpoint of the demand management, a methodology should be developed to know the load composition ratio and the shape of the daily load curve. In this paper, the relative coefficient and average load information for each load group obtained from the survey are used besides peak load and total average load. A mathematical model is proposed to derive the load composition ratio in the form of a Quadratic Programming and the load forecasting is performed using simple linear regression with future indicators. The effectiveness of the proposed method is confirmed for the Philippine island region supported by Korea Energy Agency and the Asian Development Bank.

오염부하지속곡선(LDC)을 이용한 요천A 목표수질 변화에 미치는 영향 분석

하돈우 ( Don-woo Ha ),김석규 ( Seok-gyu Kim ),송창수 ( Chang-soo Song ),고광용 ( Gwang-yong Ko ) 한국환경기술학회 2016 한국환경기술학회지 Vol.17 No.2

수질오염총량관리제 시행으로 목표수질 지점에 대해 8일 간격으로 유량 및 수질을 측정하여 목표수질 달성여부를 확인하고 수질모델링 등 기초자료로 이용하고 있다. 이렇게 측정된 자료의 추가 활용방안으로 본 연구에서는 섬진강 수계 요천A에 대해 목표수질 달성여부를 부하지속곡선을 활용하여 평가하고 초과구간 및 초과량을 분석하였다. 또한, 분석된 결과에 따라 오염물질별 수질변화의 요인을 강우, 수온, 유량 등으로 분석하고 변화 요인이 수질에 기인한 관계여부를 분석하였다. 그 결과, BOD는 겨울철 수온저하와 유량감소요인에는 관련성이 많은 것으로 나타났으며, 강우와는 관련성이 거의 없는 것으로 나타났다. T-P는 겨울철 수온저하와 유량감소요인에는 관련성이 적은 것으로 나타났으며, 강우와 관련성이 큰 것으로 나타났다. 이와 같은 결과로 요천A 단위유역이 점오염원 보다는 비점오염원에 영향이 큰 것으로 판단되어진다. Monitoring data of discharge and water quality is used as very important data for the implementation of total maximum daily load. Flow duration curve and load duration curve can be developed by linking the daily flow data of stream monitoring network to 8 day interval flow data of the unit watershed. This paper focused on the relationship between monitoring data of discharge and water quality in Yochon A unit watershed. According to the analytical results using water quality and discharge monitoring data in the Yochon A unit watershed at Seomjin river, BOD is related to temperature decline, discharge decrease and rainfall not relevant. T-P is not relevant water temperature decline, discharge decrease and rainfall related. The same result is judged for their big impact on nonpoint source than point source.

전력계통 Peak-Shaving 성능향상을 위한 부하곡선 생성

손수빈(Subin Son),송화창(Hwachang Song) 한국지능시스템학회 2014 한국지능시스템학회논문지 Vol.24 No.2

본 논문은 Peak Shaving 알고리즘의 성능 향상을 위한 예측 부하 곡선의 생성의 한 방법을 제시한다. 여기서 논하는 Peak Shaving 알고리즘은 대용량의 배터리 에너지 저장시스템 (BESS, Battery Energy Storage System)을 위한 PMS (Power Management System)의 장주기 스케쥴링 알고리즘을 의미한다. 위의 PMS는 주로 배터리에서 에너지의 입출력을 제어하는 데에 주목적이 있다. 이를 위해서 Peak Shaving 알고리즘이 사용되는데, 여기서 예측 부하곡선과 실제 부하곡선 사이의 불확실성이 나타난다. 원활한 에너지의 충,방전을 위하여 본 논문에서는 주 단위의 표준화 방법과 계절별 부하의 특성을 고려한 예측 부하 곡선 생성 방법을 제안한다. This paper suggests a way of generating one-day load curves for performance improvement of peak shaving in a power system. This Peak Shaving algorithm is a long-term scheduling algorithm of PMS (Power Management System) for BESS (Battery Energy Storage System). The main purpose of a PMS is to manage the input and output power from battery modules placed in a power system. Generally, when a Peak Shaving algorithm is used, a difference occurs between predict load curves and real load curves. This paper suggests a way of minimizing the difference by making predict load curves that consider weekly normalization and seasonal load characteristics for smooth energy charging and discharging.

수질오염총량관리를 위한 4대강 수계 장기유황곡선 작성방안

박준대 ( Jun Dae Park ),오승영 ( Seung Young Oh ) 한국물환경학회 2013 한국물환경학회지 Vol.29 No.3

Flow duration curve (FDC) can be developed by linking the daily flow data of stream flow monitoring network to 8-day interval flow data of the unit watersheds for the management of Total Maximum Daily Loads. This study investigated the applicable method for the development of long term FDC with the selection of the stream flow reference sites, and suggested the development of the FDC in 4 river basins. Out of 142 unit watersheds in 4 river basins, 107 unit watersheds were shown to estimate daily flow data for the unit watersheds from 2006 to 2010. Short term FDC could be developed in 64 unit watersheds (45%) and long term FDC in 43 unit watersheds (30%), while other 35 unit watersheds (25%) were revealed to have difficulties in the development of FDC itself. Limits in the development of the long term FDC includes no stream monitoring sites in certain unit watersheds, short duration of stream flow data set and missing data by abnormal water level measurements on the stream flow monitoring sites. To improve these limits, it is necessary to install new monitoring sites in the required areas, to keep up continuous monitoring and make normal water level observations on the stream flow monitoring sites, and to build up a special management system to enhance data reliability. The development of long term FDC for the unit watersheds can be established appropriately with the normal and durable measurement on the selected reference sites in the stream flow monitoring network.

수질오염총량관리 단위유역 유량자료와 하천유량 측정망 자료의 연계성 분석

박준대 ( Jun Dae Park ),오승영 ( Seung Young Oh ) 한국물환경학회 2013 한국물환경학회지 Vol.29 No.1

It is very difficult to apply stream flow data directly to the management of Total Maximum Daily Loads because there are some differences between the unit watershed and the stream flow monitoring network in their characteristics such as monitoring locations and its intervals. Flow duration curve can be developed by linking the daily flow data of stream monitoring network to 8 day interval flow data of the unit watershed. This study investigated the current operating conditions of the stream flow monitoring network and the flow relationships between the unit watershed and the stream flow monitoring network. Criteria such as missing and zero value data and correlation coefficients were applied to select the stream flow reference sites. The reference sites were selected in 112 areas out of 142 unit watersheds in 4 river basins where the stream flow observations were carried out in relatively normal operating conditions. These reference sites could be utilized in various ways such as flow variation analysis flow duration curve development and on for the management of Total Maximum Daily Loads.

오염부하지속곡선(LDC)을 이용한 수질오염총량관리 단위유역 목표수질 달성여부 평가방법

박준대 ( Jun Dae Park ),오승영 ( Seung Young Oh ) 한국물환경학회 2012 한국물환경학회지 Vol.28 No.5

Load Duration Curve(LDC) is a useful tool for analyzing water quality characteristics under various stream flow conditions. This study investigated the methods to identify impaired waterbodies in the assessment of water quality goal attainment by using LDC for the management of Total Maximum Daily Loads (TMDLs). Three methods were proposed. Non-typical regime exclusion method is a method to exclude water quality observations in the non-typical extreme flow conditions in order to minimize the influence of non-ordinary water quality. Flow regime weighted average method is a method to calculate weighted mean water quality instead of arithmetic mean in order to consider water characteristics properly on stream flow regime in addition to the effect of Non-typical regime exclusion method. Load exceeded interval comparison method is a method to compare the intervals between the attained and non-attained load duration periods on the LDC. The assessment of water quality goal attainment can be performed more reasonably and precisely considering water quality variations on stream flow conditions by applying these proposed methods.